1. Field of the Invention
The present invention relates to an automatic analyzer which analyzes the components of a test sample extracted from a test object and a reagent storage of the analyzer and, more particularly, to an automatic analyzer and its reagent storage which can store and cool reagents.
2. Description of the Related Art
An automatic analyzer is targeted for biochemical test items, immunological test items, and the like. The automatic analyzer obtains the concentrations of various components and the activities of enzymes in test samples by measuring changes in color tone and the like which are caused by reactions of mixtures of the test samples dispensed into reaction vessels and reagents corresponding to the respective items. This automatic analyzer performs measurement of an item selected in accordance with a test from many items made measurable upon setting of analytical conditions for each test sample. The test sample and a reagent corresponding to the selected item are dispensed into a reaction vessel with a sample probe and a reagent dispensing probe, and the mixture of the dispensed test sample and reagent is stirred by a stirrer. A photometric unit then performs measurement of the mixture.
Reagent bottles equal in number to measurable items are stored in a reagent case in a reagent storage and a reagent cover which covers the reagent case. The stored reagent bottles are kept cool to prevent analytical data from deteriorating upon degeneration of the reagents. As a method of keeping reagent bottles cool, there is available a method of cooling the reagent case and keeping the reagent bottles cool by natural diffusion of cool air in the reagent case. There is also known a keeping cool method which can make uniform a temperature distribution by sending cool air around the reagent bottles in the reagent case regardless of the arrangement of the reagent bottles in the reagent case (see, for example, Jpn. Pat. Appln. KOKAI Publication No. 2005-283529).
According to the method of keeping a reagent case cool, however, the temperature distribution of air in the reagent case is not uniform. This makes it impossible to keep the reagents in all the reagent bottles in the reagent case at a predetermined temperature. According to the method of sending cool air into the reagent case, if many reagent bottles are stored, since cool air is blown against only partial surfaces of the reagent bottles, it takes much time to lower the temperature of each bottle to a predetermined temperature. Furthermore, the reagent bottles are stored while the cover is open. As a consequence, evaporation increases the reagent concentrations to deteriorate analytical data.